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Treatise on 

Moulding Sand 




H. S. VROOMAN 

18th Place and Sangamon St. 
CHICAGO, ILLINOIS 






A TREATISE ON 
MOULDING SAND 

.By H . S . V R O O M A N . 



*8> 



Copyrighted 1904 

By H. S. V R O O MA N~ 

Chicago 




ILIBRaRY cJ CONGRESS 
Two Cepies Received 



H. S. VROOMAN 

18th Place and Sangamon St. 
CHICAGO, ILL. 




'.". .'§bfipFtir& of 'eye^y grade of 
Moulding Sand for all grades 
of work. 



The Henry O. Shepard Co., Printers, Chicago 



A TREATISE ON 
MOULDING SAND 

IN the selection of a moulding sand 
there is no rule that can be laid 
down for the selection of sand 
for a particular grade of work, as all 
foundries differ some in their oper- 
ation and practice. 

A sand that suits one foreman an- 
other can not use or would not have. 
This is not a difference in ability, but 
in conditions. A sand used in differ- 
ent shops under like conditions will 
give like results, but under different 
conditions will not give like results. 
Every practical man in the foundry 
business has his ideal in a moulding 
sand, although he is seldom able to 
obtain it. We frequently hear certain 
sands spoken of as being the best sand 
on earth. Yet, if a visit could be paid 
to the foundries located in the district 
that this sand comes from, you would 
find the usual conditions, i. e., an occa- 
sional scab or draw-down, and if the 
books could be seen, the percentage of 
loss would be the same as elsewhere. 
These losses will occur in the best 



shops, with the best of moulding sand. 
The only thing that can be done is 
to keep them down to a minimum, 
which can be done with a sand suit- 
able for your work. In ordering sand, 
allowance must be made for variation, 
as it is hardly possible you will receive 
any two shipments that are exactly 
alike. This variation is due to the way 
sand lays in the pit. Sand deposits, in 
most cases, are but pockets, being 
washed in at some time by a flood or 
overflow, and are usually found in the 
vicinity of streams or bodies of water. 
Some deposits contain two and even 
three grades of sand. These are all 
mixed together as a whole and 
shipped, unless the different grades 
are so separated that they can be mined 
separately. 

Moulding sand is really manufac- 
tured at the pit, and it is the ability 
of the shipper in the manipulation of 
the sand to put it on the market to suit 
his customers, and a shipper that un- 
derstands his business will be able to 
deliver regularly a good average grade 
of sand. The time of the year at 
which sand is dug will make a differ- 
ence in the quality. A sand digs best 



when it is of a temper to work, con- 
taining just enough water to mix well 
and soften up easily. Wet sand will 
not mix well, as the alumina rolls 
down and sticks together, neither is 
sand that is dug dry good, as the alu- 
mina is dried up in lumps and can not 
be broken. If it were possible to dig 
sand and allow it to weather out over 
winter and ship it the following sea- 
son, it would be of much more uni- 
form quality. The expense attached 
to this method of loading sand would 
increase the cost too much and the 
foundries would not want to pay the 
difference. Not being able to lay 
down a rule for the selection of a 
sand for different grades of work, 
owing to the different conditions under 
which it is used, the question then 
arises : What is a good moulding sand ? 
What kind of sand shall be selected 
and how shall this selection be made? 
To begin with, a good moulding sand 
will resist the pressure of the liquid 
metal,, give free escape to the gases, 
separate easily from the castings when 
cool, leaving a clean, smooth surface. 
To fill the first requirement, the sand 
must contain sufficient alumina or 



bond to resist the pressure of the 
liquid metal ; this must be kept within 
reason or it will not permit the free 
escape of the gases. The amount 
must be determined by experiment. 
Railroad work will burn out sand 
faster than agricultural castings and 
will require a sand higher in alumina, 
etc. All sand will burn out or lose 
its plastic nature at a red heat and to 
the^ extent that a sand becomes red- 
hot from the face of the mould, to that 
depth will it burn out and become a 
loss and to that amount must be re- 
newed, and while on that point it 
might be well to say that a sand heap 
should have a little new sand every 
day. The theory held by some that 
the new sand that is put into the fac- 
ing sand is enough to keep the heap 
in good condition is wrong. There 
is nothing as hard on sand as sea coal. 
This facing sand is all brought in con- 
tact with the melted iron and if it does 
not burn out from contact with the 
casting it is burned out from the sea 
coal taking fire and the passage of 
gases through the pores left open by 
burning out of the coal. The renewal 
of a sand heap is a thing which should 



be looked after carefully, as many 
losses that are laid to the sand are the 
result of rotten sand heaps. This re- 
newal should not be left to the men, 
but should be seen to by the foreman, 
and the proper amount of new sand 
put into the heaps every day. The 
more open a sand is the easier it will 
separate from the castings. To secure 
a smooth face use as fine a sand as 
you can without it burning on to the 
face of the casting. It is advisable to 
use as open a sand as you can without 
it cutting, as an open sand will carry 
more water, which will aid in giving 
better lifts and clean draws. You can 
ram it harder, which will keep the 
casting down to weight, and it will 
vent easier. In making a test of a 
sand a thorough trial should be given, 
and when failure is met with an analy- 
sis of the causes as well as the compo- 
sition should be made and the exact 
fault located. It may be found under 
careful scrutiny that a sand you 
would condemn offhand may be used 
to advantage when it is thoroughly 
understood. In making the analyses 
of sands, three determinations are all 
that are necessary — (i) alumina, (2) 



free silica, (3) loss on ignition. The 
alumina denotes the strength or wear- 
ing qualities, free silica the openness 
or porosity, the loss upon ignition the 
water of crystallization and vegetable 
matter. To this might be added a 
determination for iron; sand that is 
very red in color will analyze high in 
iron. Iron adds a further bond to the 
sand in addition to the alumina, with- 
out closing up the pores. Impurities, 
such as lime and magnesia, as a rule 
do not exist in sufficient quantities to 
do any harm, and can be ignored. 
After you have decided on about the 
grade of sand you want to use, you 
may then have trouble in finding what 
you want. The next move is for you 
to buy two or more grades of sand 
and blend them. This is the only solu- 
tion of the moulding sand problem 
and the one way for the foundry men 
to get good sand and one containing 
the proper percentage of the different 
elements. By this method a coarse 
sand can be made finer by the addi- 
tion of fine sand, and a fine sand can 
be made coarse by adding coarse sand, 
etc. Your percentage of ^lumina can 
be increased or decreased! at will by 



adding open or strong sand in propor- 
tions to suit your work. By blending 
I do not mean to buy two or three 
grades of sand and put them all in 
one bin or shed, or put them in differ- 
ent sheds and allow the moulder to dig 
into them at will. These sands should 
be bought differing in composition and 
structure to the extent that they may 
be used separately on some of your 
work and when mixed together will 
give you a sand that you can use 
generally. The blending process should 
be done with a mechanical mixer, a 
machine that every foundry should 
have. This should not be a machine 
that will throw the sand out as fast 
as it is put into it, but a machine that 
will mix it thoroughly. Care should 
be taken in mixing and the proper 
proportions used. Mix by measure 
and not by weight, as one sand may 
contain more water than the other and 
would weigh more. Should your sand 
go back on you for any reason in the 
blending process, you have the means 
at hand by which you can remedy the 
trouble at once. You do this in your 
mixture of iron, why not in sand? 
Local sands are not alwavs suitable for 



local work, but by the blending proc- 
ess an inferior local sand can be built 
up by mixing with it a good foreign 
sand. I have before me the analyses 
of two sands. No. 2-E, a coarse sand 
suitable for machinery and general 
jobbing. The No. 80, a medium grade, 
suitable for agricultural, malleables 
and medium-weight castings. We have 
sold these sands for years and they 
have given entire satisfaction for this 
purpose. These two sands come from 
different States, and as an example of 
what can be done with them by the 
blending process, we will mix for 
example fifty per cent of each. The 
analyses are as follows : 



Analysis No. 2 Sand, Coarse. 

Per cent. 

Loss on ignition 3.98 

Silica 79.22 

Oxide of iron 5.21 

Oxide of aluminum 9.86 

Calcium oxide .80 

Magnesium oxide ^93 

Total 100.00 



Fineness No. 2 Sand. 

Per cent. 

20-mesh 96.08 

40 " 72.60 

60 " 26.77 

80 " 21.05 

100 " 15.40 



The percentage of sand passing 
through the different mesh sieves : 

Analysis No. 80 Sand, Medium. 

Per cent. 

Loss on ignition 3.36 

Silica 80.57 

Oxide of iron 7.05 

Oxide of aluminum 8.67 

Calcium oxide 35 

Magnesium oxide Trace 

Total 100.00 

Fineness No. 80 Sand. p er cent. 

20-mesh 98.87 

40 " " 83.24 

60 " 67.72 

80 " 63.16 

100 " 54-U 

BLENDED ANALYSES. 

Per cent. 

Loss on ignition 3.67 

Silica 79-895 

Oxide of iron 6.13 

Oxide of calcium 9-265 

Calcium oxide 575 

Magnesium oxide 465 

100.000 
Fineness of blended sands : Per cent 

20-mesh 97-47 

40 " 77-92 

60 " 47.24 

80 " 42.10 

100 " 34-75 

The blending of these two sands is 
for the purpose of changing their 
physical structure and not the chem- 
ical, as the two sands analyze very 
nearly alike. But the chemical analyses 



of sands can be changed just as read- 
ily by the same methods. The usual 
complaints about sands are that they 
are either too coarse or too fine, and it 
is to show how this difficulty can be 
overcome that these two sands are 
used. By the process the fine sand is 
made coarser and the coarse sand the 
reverse, and you have in the blended 
sand an intermediate grade, something 
that is very hard to find in nature. 
The blended analysis is found by add- 
ing together the determination of the 
same element in both sands and divid- 
ing it by two, as the sand is mixed 
fifty per cent of each. For example, 
the silica of the No. 2 sand is 79.22 
per cent and of the No. 80 it is 80.57 
per cent. The sum of the two is 159.79 
per cent, divided by 2 leaves 79.89 per 
cent, the silica of the blended sample. 

Per cent. 

Silica of No. 2 Sand 79.22 

Silica of No. 80 Sand 80.57 

2) 15979 

Silica, blended sand 79-89 

The same is done with the other 
elements ; also use the same method 
in the determination of the fineness of 



the blended sample. In figuring these 
analyses they have only been carried 
out two places. 

In gauging the fineness of these two 
sands an average sample is taken of 
each and passed over five different 
mesh sieves from a No. 20 mesh up to 
100 mesh to the inch. The percentage 
passing through each sieve is used in 
the determination for fineness. By 
adding together the amounts that 
passed through each different sieve 
and dividing, this by 5, the number of 
sieves used, it will give you the aver- 
age per cent that passed through, all 
the sieves, which number you can use to 
designate the grade of your sand ; for 
example, the total amount of the No. 
2-E sand passing through the different- 
sized sieves is 231.90 per cent, divided 
by 5 equals 46.38 per cent, the average 
per cent passing through all the sieves. 
This will be the average grade of this 
sand. On the No. 80 sand the total 
passing through all the sieves is 367.10 
per cent, divided by 5 gives 73.42, the 
average per cent passing all the sieves, 
which will be the average grade of the 
No. 80 sand. By taking the difference 
between these two sands you are able 



to tell how much finer one sand is than 
the other. 

No. 2-E Sand. 

Per cent. 
20-mesh 96.08 

40 " 72.60 

60 " 26.77 

80 " 21.05 

100 " 15.40 

5) 231.90 

Average fineness No. 2-E Sand... 46.38 

No. 80 SAND. Percent. 

20-mesh 98.87 

40 " 83.24 

60 " 67.72 

80 " • .. 63.16 

100 " 54-H 

5) 367-10 

Average fineness No. 80 Sand 73-42 

Per cent. 

No. 80, average fineness 73-42 

No. 2-E, average fineness 46.38 

Difference 27.04 

By the above it will be seen that 
there was 27.04 per cent more of the 
No. 80 sand passed through all the 
sieves than there was of the No. 2-E 
and is therefore that much finer. By 
adding up the fineness of the blended 
sample it will be seen that the average 
percentage that passed through all the 

Continued on page 16. 



A CARD 



OUR object in sending out this lit- 
tle book is to get you to place 
your order for moulding sand with us. 
Our long experience in the business 
places us in a position to furnish you 
with every known grade of moulding 
sand. Our sand pits are so located that 
we are able to reach all points in the 
Middle and Western States with a 
minimum freight rate, and we are 
able to deliver at a reasonable price a 
grade of moulding sand that you can 
not find locally. We want your busi- 
ness and if you will give us a trial 
you will be pleased with the results. 
In addition to the moulding sand, we 
manufacture and carry in stock a 
complete line of foundry supplies, 
foundry facings, plumbago and silver 
lead, fire brick, etc., on which we so- 
licit your business. 

Hoping to be able to serve you, I 
am, Yours truly, 

H. S. Vrooman. 



MAR 19 1904 

sieves is 59.9 per cent, a grade just 
between the two sands. It is a hard 
matter to convey by words the change 
that has been wrought in these two 
sands by blending them. They must 
be seen to be appreciated, and to 
those interested we will be pleased 
to send, on application, samples of 
these sands or any of the sands which 
we mine. We have a large number of 
moulding sands suitable for all classes 
of work and for blending purposes. 
If you are having trouble with your 
sand or seeking to improve your cast- 
ings and will write us, we will be 
pleased to furnish you with any infor- 
mation we have. 

H. S. Vrooman. 



D O N OT FAI L TO 
WRITE FOR OUR 
= COM PLETE = 
= CATALOGUE = 
ON FOUNDRY FACING 
FOUNDRY SUPPLIES 
FIRE BRICK, ETC. 



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